3,535 research outputs found
Studying International Migration in the Long(er) and Short(er) Duree: Contesting Some and Reconciling Other Disagreements Between the Structuration and Morphogenetic Approaches
The essay contests some and reconciles other disagreements between the structuration and morphogenesis approaches?the two models in present-day sociology which aim at bridging the macro-micro gap in social theorizing, but whose advocates have been either indifferent to or at open odds which each other instead of engaging in a close intellectual collaboration. The empirical illustrations of my arguments come from local statistical surveys and ethnographic studies conducted in Polish villages from the onset to the decline of mass transatlantic migration in the period 1870s-1930s
Different Times, Different Places, Different Standpoints
[No abstract][No keywords]
Inherent Agency Conflict Built into the Auditor Remuneration Model
This paper provides a model for audit market interventions. The study asks whether interventions in the audit market result in excessive premiums at the cost of quality and independence. The model was tested based on a historical data sample of 1,927 companies’ fiscal year financial statements, observed for the period 2010–2013. The testing strategy combined statistical analysis of the market concentration and regression of abnormal results. The findings do not support, for the Polish market, the conclusion that the audit market is used as a leverage for consulting services. This paper discusses possibilities of systematic risk for policymakers as a result of the negative interaction between regulated and non-regulated markets
Monitoring charged particles in indoor air using a neutral cluster and air ion spectrometer
While there are sources of ions both outdoors and indoors, ventilation systems can introduce as well as remove ions from the air. As a result, indoor ion concentrations are not directly related to air exchange rates in buildings. In this study, we attempt to relate these quantities with the view of understanding how charged particles may be introduced into indoor spaces
Ions in motor vehicle exhaust and their dispersion near busy roads
Measurements in the exhaust plume of a petrol-driven motor car showed that molecular cluster ions of both signs were present in approximately equal amounts. The emission rate increased sharply with engine speed while the charge symmetry remained unchanged. Measurements at the kerbside of nine motorways and five city roads showed that the mean total cluster ion concentration near city roads (603 cm-3) was about one-half of that near motorways (1211 cm-3) and about twice as high as that in the urban background (269 cm-3). Both positive and negative ion concentrations near a motorway showed a significant linear increase with traffic density (R2=0.3 at p<0.05) and correlated well with each other in real time (R2=0.87 at p<0.01). Heavy duty diesel vehicles comprised the main source of ions near busy roads. Measurements were conducted as a function of downwind distance from two motorways carrying around 120-150 vehicles per minute. Total traffic-related cluster ion concentrations decreased rapidly with distance, falling by one-half from the closest approach of 2m to 5m of the kerb. Measured concentrations decreased to background at about 15m from the kerb when the wind speed was 1.3 m s-1, this distance being greater at higher wind speed. The number and net charge concentrations of aerosol particles were also measured. Unlike particles that were carried downwind to distances of a few hundred metres, cluster ions emitted by motor vehicles were not present at more than a few tens of metres from the road
Spatial variation of particle number concentration in school microscale environment
There is significant toxicological evidence of the effects of ultrafine particles (<100nm) on human health (WHO 2005). Studies show that the number concentration of particles has been associated with adverse human health effects (Englert 2004). This work is part of a major study called ‘Ultrafine Particles form Traffic Emissions and Children’s Health’ (UPTECH), which seeks to determine the effect of the exposure to traffic related ultrafine particles on children’s health in schools (http://www.ilaqh.qut.edu.au/Misc/UPT ECH%20Home.htm). Quantification of spatial variation of particle number concentration (PNC) in a microscale environment and identification of the main affecting parameters and their contribution levels are the main aims of this analysis
Application of bag sampling technique for particle size distribution measurements
Bag sampling techniques can be used to temporarily store an aerosol and therefore provide sufficient time to utilize sensitive but slow instrumental techniques for recording detailed particle size distributions. Laboratory based assessment of the method were conducted to examine size dependant deposition loss coefficients for aerosols held in VelostatTM bags conforming to a horizontal cylindrical geometry. Deposition losses of NaCl particles in the range of 10 nm to 160 nm were analysed in relation to the bag size, storage time, and sampling flow rate. Results of this study suggest that the bag sampling method is most useful for moderately short sampling periods of about 5 minutes
Relation Between Particle Mass and Number for Submicrometer Airborne Particles
The relationship between particle mass and the number of ambient air particles for the submicrometer size range was examined using a Tapered Element Oscillating Microbalance to determine the mass concentration, and a Scanning Mobility Particle Sizer to determine the volume concentration and total number of particles. After validating the techniques through their application to the estimation of submicrometer particle density for two laboratory generated aerosols of known bulk density (Sodium Chloride and Di-2-ethylhexyl-sebacate), the submicrometer fraction of laboratory generated Environmental Tobacco Smoke and ambient air were examined and an estimate of the average submicrometer particle densities for these aerosols found to be 1.18 g cm-3 and 1.7 g cm-3 respectively
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